The present invention relates to a new and improved thermal imaging system, and more particularly to a thermal imaging system that provides the wearer with a thermal image in the wearer's field of view permitting the wearer to see objects radiating thermal energy in the infrared spectrum. Otherwise such objects would be obscured from the wearer's view due, for example, to dense smoke encountered in a fire. The thermal imaging system also permits viewing of fire or other hot spots radiating energy in the infrared range but obscured, for example, by a wall or a roof.
Thermal imaging systems are known in the art for providing a person with an image of objects radiating energy in the infrared range. Also known are combination helmet and thermal camera arrangements such as disclosed in U.S. Pat. No. 5,089,914, issued Feb. 18, 1982, and hereby incorporated by reference as if fully reproduced herein.
However, there still exists a need in the art for a new and improved thermal imaging system which is particularly useful when embodied as a combination fireman's facepiece thermal imaging system wherein the thermal imaging system is advantageously mounted to provide the fireman with hands-free wearing of the facepiece and the thermal imaging system. The fireman's ability to wear the combination while engaged in fire fighting provides the fire fighter with the thermal image of objects he cannot otherwise see with his natural eyesight, such as, for example, bodies of unconscious but alive fire and smoke victims present at a fire scene. There also exists a need in the fire fighting art for mounting the thermal or infrared camera of such a thermal imaging system in a temperature protected manner so as to reduce the influence of a heated environment such as is present at a fire scene, on the camera which is thermal sensitive.
Firefighters, emergency responders and some industrial workers are exposed to extremely hazardous, toxic and hostile atmospheres in the fulfillment of their assigned duties. To accommodate the lethal atmosphere, these workers use what is called self-contained breathing apparatus. The self-contained breathing apparatus most often is an open-circuit breathing apparatus where compressed air is carried on the back in a carefully engineered, user friendly harness which spreads the load of the cylinder weight onto the user in a way that minimizes the discomfort and exhaustion carrying that weight might otherwise cause.
The self-contained breathing apparatus provides fresh, breathable air to the user while he is in an atmosphere that is hostile. In many cases, this hostile atmosphere either is or can quickly become difficult to see through. For firefighters particularly, this is the most common experience in an actual structural fire fight. At the very moment when their eyesight is of its premium value to them, they lose sight completely because the denseness of the smoke that surrounds them. Not even the fire itself can be seen through this atmosphere much less anyone they might be trying to find and rescue or any other hazards that might impede their escape or injure them, which might be avoidable if they could see.
For some workers, night work is also a factor. The lack of light or the potential loss of light should the artificial means of lighting fail, might render the worker in a dangerous situation which he could avoid if he could see.
Thermal imaging systems are available in a relatively large, bulky and hand-held format. These thermal imagers operate very effectively, but their hand-held nature turns the user into a "cameraman" because the camera completely occupies his hands and attention. Also, helmet mounted thermal imaging systems have been proposed such as disclosed in U.S. Pat. No. 5,089,914 and EP 0 822 030 A1, hereby incorporated by reference as if fully reproduced herein.
In EP 0 622 030 A1 the image sensor itself, along with a very limited amount of electronic processing equipment are mounted to a pod below the rim of the helmet with a heads-up display mounted at the front of the helmet. A counterweight is mounted at the rear of the helmet, and a power and electronic processing unit is displaced from the helmet by a series of wires. This product made the helmet mounted thermal imager an actual practicality for a broad spectrum of uses, not the least of which is firefighting and emergency response.
Helmets are still very heavy. Neck fatigue remains a factor, and continuity of operations also becomes more difficult because when the need for the thermal imager and its additional weight are removed as a consequence of the atmosphere becoming clear and/or breathable, the thermal imager user typically has to remove himself from the scene, whatever the remaining work might be, in order to remove the very heavy helmet and put his own lighter helmet back on and go back to work. The interruption can be at best a nuisance and at worst a potentially dangerous situation. The size of the helmet with its mounted thermal imager is too large to display to some other part of the body and switch-out helmets while working.
Based upon their assessment of the situation, the firefighters, emergency responders or workers may elect to go in to their work environment without a helmet mounted system, and instead use their normal personal helmet. The atmosphere could then deteriorate, forcing a retreat and precious time lost to re-equip themselves with the helmet mounted system before handling the work in the darkened environment.
Because the thermal image sensor in helmet mounted systems and hand-held systems are mounted in a captive atmosphere (encased in a protective envelope), the sensor is prone to overheating and when this occurs the sensor "whites out", negating any image at a moment when a user might critically need it. Each of the different technologies has a different level of heat sensitivity before this "white out" occurs. Because the sensor is mounted in a static atmosphere in its protective containment, any prolonged exposure to high heat will eventually have this effect.
The match up of the thermal imager to the helmet did relieve the user of his need to hold the imager with his hands. This is an advantage of the helmet mounted systems over hand-held systems. However, the helmet mounted systems are not matched in a way to maximize the utility of both the helmet and the thermal imager. The helmet is used in just about any and every potentially dangerous work environment. The thermal imager is only used when an atmosphere becomes so hostile and dark that it renders the worker blind. Self-contained breathing apparatus matches, more exactly, the work environment in which the thermal imager is needed.
The wires and harnesses that link the helmet mounted thermal image sensor and heads-up display with the power and electronic processing unit worn on the firefighter's body somewhere, are another set of wires and/or potential snag hazards that the user must deal with and think about as he is using the equipment.